And having slept on the LOS rules a night, I'm "starting to get it." But, having said that, I'm siding with Steven Bucey in the most general sense that the LOS rules are poorly written.
I really struggled on HOD3 last night to a paralyzing degree, wanting to "get it right," that I didn't finish the moving the first counters because I was trying to determine of the Germans had LOS for Opportunity Fire. Trying to figure out why a "downhill" crestline blocked LOS and referring to Consimworld discussions, it was confusing.
Some of the confusion arises from how Lewis describes crestlines as slopes, not cliffs. Assuming a gradual slope from L3 to L1 on clear hexes, what's blocking?
I'm tempted to say Section 5 just needs a rewrite altogether, with more graphics and samples. It's not just 5.4.4. Really.